Collective functionalities emerging in living active matter
 

Organisms often cooperate to perform functions that they cannot do alone. However, this puzzle of how biological self-organization emerges from the collective dynamics of individual constituents remains unsolved. In this talk, I will discuss some of these collective functionalities, including communication, navigation, and cooperative nutrient transport. First, we will explore how bacteria can reorient against flows and swim upstream [1]. Second, we consider how cells generate their own flows to transport nutrients [2], and how “active carpets” like biofilms can lead to enhanced non-equilibrium diffusion [3]. Finally, we focus on ultra-fast communication through “hydrodynamic trigger waves”, signals between cells that propagate hundreds of times faster than their swimming speed [4]. Together, these ideas help us understand emergent self-organization in biological systems and the design space of active materials.

 [1] Torres et al., “Enhancement of bacterial rheotaxis in non-Newtonian fluids”, Proc Nat Acad Sci. (2024)
[2] Jin et al. “Collective entrainment and confinement amplifies transport by schooling micro-swimmers”, Phys. Rev. Lett. 127: 088006 (2021) 
[3] Guzman-Lastra et al. “Active carpets drive non-equilibrium diffusion and enhanced molecular fluxes,” Nat. Commun. 12: 1906 (2021)
[4] Mathijssen et al. “Collective intercellular communication through ultra-fast hydrodynamic trigger waves,” Nature 571, 560-564 (2019)